1. Field of the Invention
The present invention relates to a teaching apparatus for robot.
2. Description of the Related Art
A robot is controlled to move along a preliminarily prepared track. The track of the robot can be prepared based on a teaching position and a speed, which are designated by an operator. The teaching position can be set by an operator's operation via an operation panel. The operator operates the teaching operation panel to, for example, set the robot at a desired position and posture. The operator can store, as a teaching point, the position, at that time, of the tip point of a tool in the robot, in a control device. The operator can also store the posture of the robot in the control device. Further, the control device can drive the robot so that the robot passes through the teaching point or passes the vicinity of the teaching point. The position and the posture of the robot are determined based on the teaching position, and accordingly, it is preferable to accurately teach the teaching position to the robot.
Japanese Unexamined Patent Publication No. 2002-160183A discloses a robot used in a substrate processing system. This publication discloses a teaching operation for indirectly identifying the position of a robot by positioning a position adjusting pin at a predetermined hole.
When teaching a teaching position to a robot, it is difficult to manually move the robot to a desired teaching position in some cases. There is, for example, an operation for teaching a teaching position in an operation for attaching a workpiece to a predetermined member. In this operation, when an operator can verify the portion to which the workpiece is attached, it is easy to teach the teaching position for the robot. However, in some cases, the portion to which the workpiece is attached is located at a retracted portion of a recessed part, or is located on the inside of a hole. In such a case, when the workpiece is introduced into the recessed part or the hole, both the workpiece and the attachment position cannot be seen, and it is difficult to manually move the robot to a desired teaching position.
In the above teaching method in Japanese Unexamined Patent Publication No. 2002-160183A, a position adjusting pin is inserted into a predetermined reference hole, to determine the position of a robot. Thus, the accuracy of the teaching position depends on the accuracy of the relative position of the position adjusting pin to the reference hole. Tightly fitting of the position adjusting pin to the reference hole improves the accuracy of the teaching position, but increases the difficulty of fitting the position adjusting pin to the reference hole. Consequently, a teaching operation requires a long period of time. In contrast, loose fitting of the position adjusting pin to the reference hole reduces the accuracy of the teaching position.